Printer mounting arrangement
FIELD OF THE INVENTION 
     The present invention relates to printers, and more particularly relates to a novel arrangement whereby a printer can be provided as an integral component of a computer or other electronic apparatus. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     A printer is a virtually essential accessory for use with a computer. In some applications, however, such as those in which the computer is of the &#34;portable&#34; or &#34;transportable&#34; type, it is awkward to provide a printer. The unit must be carried separately, and connected and disconnected from the computer and from a power source each time it is used and moved. Other printer inconveniences arise with computers that are rack mounted, and in situations in which space is limited. If the computer is rack mounted, a separate rack must usually be dedicated to the printer. If space is limited, the additional &#34;footprint&#34; area required by the printer can rival that required by the computer itself. 
     In accordance with the present invention, these problems are overcome by mounting a printer assembly within the case of a computer. In one embodiment, the printer assembly is sized and adapted for mounting in an industry standard drive bay, of the sort with which most computers are equipped. The assembly is fixedly mounted in this bay behind a front panel, and paper printed thereby is routed out an opening in the panel. In another embodiment, the printer is mounted in a recess in a computer case, such as in a drive bay, and is slidable between first and second positions. In the first position, the printer is disposed within the case, concealed and secure from abuse. In the second position, the printer is disposed outside the case and is available for use. In both embodiments, power and data connections are made internally to the printer assembly, preferably with industry-standard connectors to facilitate installation. Such a printer assembly can be provided as a component of a computer as originally manufactured, or can be added subsequently to a computer as an accessory. 
     The foregoing and additional features and advantages of the present invention will be more readily apparent from the following detailed description thereof, which proceeds with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a printer assembly according to the present invention installed in a drive bay of a computer. 
     FIG. 2 is a perspective view showing the printer assembly of FIG. 1 in its extended position. 
     FIG. 3 is a top plan view of the printer assembly of FIG. 1 in its nested position within the case of a computer. 
     FIG. 4 is a section view of the printer assembly of FIG. 1. 
     FIG. 5 is a side view of the printer assembly of FIG. 1. 
     FIG. 6 is a partial schematic block diagram of a computer illustrating its interface to the printer assembly of FIG. 1. 
    
    
     DETAILED DESCRIPTION 
     As is familiar to those skilled in the art, computers typically are equipped with one or more &#34;bays&#34; into which disk or tape drives can be installed. Such bays are sized in accordance with industry standards to facilitate their use with a variety of after-market drive products. Standard dimensions are approximately 5.5 or 3.5 inches in width and 1.75 or 3.5 inches in height. &#34;Rails&#34; on the sides of a disk drive cooperate with support structure inside the bay to facilitate mounting of the drive in the bay. 
     Computers are also typically equipped with internal power supplies that are pre-wired to supply power to drives that may subsequently be installed in the bays. This wiring comprises power and ground wires that terminate in an industry-standard connector. This connector is of a design adapted to mate with a corresponding standard connector that is found on most disk drives. 
     Referring now to FIGS. 1-6, an exemplary printer assembly 10 includes an internal chassis 12 containing a printer mechanism 14 and an interface card 16, all adapted to be slidably mounted within a drive bay 18 of a computer 20 by a sliding mechanism 22 and an external chassis 24. 
     The illustrated printer 14 is a thermal printer, such as the Seiko STP411G-320, which can print 40 characters per line in normal mode and 80 characters per line in compressed mode. The interface card 16 interfaces the printer to an output port 26 of an associated computer 20. A suitable interface card is the Seiko IF 4112-GCB, which includes both serial and parallel inputs. (In the illustrated embodiment, a simplified version of the Seiko interface card is used and omits the parallel input port, since only one port is required.) The interface card drives an indicator LED 30 on a front panel 32 to indicate ON LINE. A pushbutton 28 operates the printer&#39;s line feed function. 
     The sliding mechanism 22 comprises left and right nested channel slide assemblies 34, 36 which couple the internal chassis 12 to the external chassis 24. The nested channel slide assemblies are commercially available from Grant Hardware Co. of West Nyack, N.Y. as part number 4435-8. 
     The external chassis 24 comprises an aluminum frame sized and shaped so the internal chassis 12 can nest therein. Attached to the sides of the frame are mounting rails 40, 42 which are dimensioned to cooperate with corresponding mechanical supports in the drive bay of the computer to facilitate mounting of the printer assembly 10 therein. The illustrated rails are designed to cooperate with mechanical supports used in a Hewlett-Packard computer. Those skilled in the art will recognize that different rails may be used to accommodate the requirements of different computers. Protruding from the rails are grounding tabs 43 that are used in the Hewlett-Packard drive bay to assure electrical continuity. 
     The internal chassis 12 is formed of sheet aluminum and defines an open chamber 44 in which a roll 46 of thermal paper rests. The thermal printing mechanism 14 is disposed along one edge 48 of this chamber, and paper from the roll 46 is routed therethrough. A paper cover door 50, having a lift tab 52, is hingedly mounted at the opposite edge 54 of this chamber to provide access to the printer. 
     A female latch element 56 is desirably mounted on a rear panel 58 of the internal chassis 12. This element cooperates with a male element 60 mounted in the rear of the external chassis 24 to hold the internal chassis nested therein. To extend the internal chassis from the external chassis, a user simply pulls on a grip 62 on the front panel 32, thereby separating the mated members and permitting the printer assembly 10 to be extended from its nested position. When the printer assembly is fully extended to its second position, latch members 63 on the sliding mechanism 22 engage to maintain the printer in this position. Release members 67 can be depressed to free the printer from its extended position and to permit sliding back to the nested position. 
     As noted, most computers include an internal power cable 64 adapted to provide power from an internal power supply 65 to disk drives that may be mounted in their drive bays. The connectors 66 used on such cables are generally standardized to facilitate connection to a variety of accessory disk drives. The external chassis 24 of the illustrated printer assembly 10 desirably includes a connector 68 (FIG. 6) on the rear panel 58 thereof adapted to mate with and receive power through such a cable. 
     The rear panel of the external chassis 24 is also equipped with a second connector 72 (FIGS. 3 and 6) adapted to receive serial data from a serial interface card 26 mounted in the computer. Again, the connectors 73 used with serial data cards are generally standardized, and the connector 72 on the rear panel of the printer is desirably adapted to mate with and receive data from such a standard connection. (In some computers, the processor board 74 contains a serial interface, so no serial card is needed.) 
     An umbilical cable 75 couples the power and data signals from the rear panel connectors 68 and 72 to a connector that mates with a connector on the interface card 16. The umbilical cable is designed to accommodate movement of the internal chassis 12 relative to the external chassis 24 when the printer is moved between its first and second positions. 
     In one embodiment of the invention, the sliding mechanism 22, when fully extended, closes a microswitch 70 on the interface card 16 that applies power to the interface circuitry and printer mechanism 14. By such an arrangement, power is applied to these elements only when the assembly is extended to its second position, ready for use. This interlock prevents inadvertent operation of the printer while nested within the case of the computer. 
     From the foregoing, it will be recognized that the provision of a printer as an integral part of a computer overcomes a great number of drawbacks that have hindered use of printers with portable/transportable/rack mount computers, and with computers used in applications where space is limited. For example, no longer must a printer and associated cabling accompany a transportable computer wherever a user contemplates a hard copy output might be required. Now, the computer itself can be equipped with a dedicated printer that is available when needed, and conveniently stored when it is not. Similarly, no longer must a user bother with connecting and disconnecting a printer to power and data each time it is required. Instead, these connections are made internally, ready at a moment&#39;s notice. 
     Having described and illustrated the principles of my invention with reference to a preferred embodiment, it will be apparent that the invention can be modified in arrangement and detail without departing from such principles. For example, while the invention has been illustrated with reference to an embodiment employing a thermal printer, it will be recognized that the principles of the invention are equally applicable to printers employing other technologies, such as ink jet, impact/dot-matrix, xerographic, etc. Similarly, while the invention has been illustrated with reference to the mounting of a printer in a computer, it will be recognized that a variety of other electronic products can benefit from provision of a printer integrally therein. Exemplary are test instruments which include one or more drive bays to facilitate software programming of certain measurement routines. Still further, it will be recognized that the invention is not limited just to equipment that includes an industry standard drive bay. Rather, any cabinet or enclosure that has adequate space therein can be adapted to receive a printer mounting arrangement in accordance with the principles of this invention. Finally, while the invention has been illustrated with reference to an embodiment in which the printer assembly is slidably mounted in a drive bay, it will be recognized that in other embodiments the printer assembly can be fixedly mounted in such a bay. In such other embodiments, paper printed by the printer can be routed through an opening in the front panel. Rolls of paper can be installed either through a doorway in the front panel, or by withdrawing the assembly from the bay. 
     In view of the many possible embodiments to which the principles of my invention may be put, it should be recognized that the detailed embodiment is illustrative only and should not be taken as limiting the scope of my invention. Rather, I claim as my invention all such embodiments as may come within the scope and spirit of the following claims and equivalents thereto.